LE BOURGET, France — Iridium Satellite LLC has opened discussions with an international body that coordinates Earth observation investment worldwide about the possible inclusion of environment-monitoring payloads on Iridium’s second-generation constellation of telecommunications satellites.

According to Iridium and other officials, the discussions still are at an early stage, but Jose Achache, director of the Geneva-based Group on Earth Observations (GEO), said he is taking the Iridium offer seriously enough to introduce it to GEO’s 70-plus national delegations at a ministerial summit scheduled for November in Cape Town, South Africa.

“We have been in fairly intensive discussions with them on several scenarios,” Achache said June 18 during a conference on environmental monitoring initiatives worldwide. “Imagine, for example, if we had altimeters on 25 low-orbiting satellites like Iridium’s. We could do real-time tsunami detection and coastal and fisheries management.”

One advantage of using Iridium as a possible carrier for environment-monitoring sensors is the constellation’s inter satellite communications capability, which makes it possible to have telephone links from one side of the world to the other without passing through many gateway Earth stations. The same feature could be used to deliver environmental data without waiting for the satellites to pass over a given ground station, Achache said.

Achache said many questions need to be answered regarding the financing of such payloads and the amount of money

Iridium would charge for their annual operation. But he said there appears to be nothing in the GEO charter that would prevent such an arrangement with a private company.

Bethesda, Md.-based Iridium operates a constellation of 66 satellites, plus several spares, flying in near-polar orbit at an altitude of about 780 kilometers.

The satellites, launched between 1997 and 1999, were designed by prime contractor Motorola to last for five years. The constellation’s principal use is for government and corporate telephone and data links.

Iridium officials say their current constellation of satellites is still healthy and will be able to continue with full service through 2013-2014. This assertion has come under closer review since Iridium’s competitor Globalstar announced that its satellite-telephone constellation has been degrading faster than predicted, forcing Globalstar to accelerate an order for replacement satellites.

Iridium has adapted its marketing strategy to attract Globalstar customers worried about satellite signal availability. Gregory C. Ewert, Iridium executive vice president for business development, said Iridium keeps constant watch on Globalstar performance by testing Globalstar phones in different regions. “I have told Globalstar people that I must be one of their biggest customers,” Ewert said here June 19 at the Paris air show.

Don Thoma, Iridium executive vice president for corporate development, said the company will issue initial requests for information in July to satellite contractors interested in building the second-generation constellation.

“It’s only to get their input into possibilities,” Thoma said. “By the end of 2008 the real development will begin.”

Iridium expects to sign a contract for the new satellite constellation in late 2008.

Thoma said GEO or any other organization interested in using the Iridium constellation’s spare on board capacity would need to make commitments by the same end-of-2008 time frame.

He said power, weight and other limits afforded to such piggyback payloads have yet to be fixed.

“What we are proposing to GEO and others is that 90 percent of the cost of getting their hardware in orbit is paid by us,” Thoma said. “We are building and launching the satellites for our core business. But there should be a way, on the model of a public-private partnership, to accommodate their hardware — say, 25- to 30-kilogram sensors on perhaps 30 satellites.”

Iridium is still a long way from financing its constellation, a capital expense that likely will require the company to access both the debt and equity markets, Ewert said.

Peter B. de Selding was the Paris bureau chief for SpaceNews.